In-stent restenosis. Acute and long-term outcomes after excimer laser coronary angioplasty.

OBJECTIVE: With the increased use of intracoronary stents, in-stent restenosis has become a clinically significant drawback in invasive cardiology. We retrospectively assessed the short- and long-term outcomes after excimer laser coronary angioplasty of in-stent restenosis. METHODS: Twenty-five patients with 33 incidents of in-stent restenosis treated with excimer laser coronary angioplasty (ELCA) were analyzed. Sixty-six percent were males, mean age of 73 +/- 11 years, and 83% were functional class III-IV (NYHA). ELCA was performed using 23 concentric and 10 eccentric catheters with a diameter of 1.6-2.2 mm, followed by balloon angioplasty (PTCA) and ultrasound monitoring. The procedure was performed in the following vessels: left anterior descending artery, 10; left circumflex artery, 8; right coronary artery, 6; left main coronary artery, 2; and venous bypass graft, 7. RESULTS: The ELCA was successful in 71% of the cases, and PTCA was 100% successful. The diameter of the treated vessels was 3.44 +/- 0.5 mm; the minimal luminal diameter (MLD) increased from 0.30 mm pre-ECLA to 1.97 mm post-ELCA, and to 2.94 mm post-PTCA (p < 0.001). The percent stenosis was reduced from 91.4 +/- 9.5% before ECLA to 42.3 +/- 14.9% after ELCA and to 14.6 +/- 9.3% after PTCA (p < 0.001). Seventeen (68%) patients were asymptomatic at 6 months and 15 (60%) at 1 year. New restenosis rates were 8/33 (24.2%) at 6 months and 9/33 (27.3%) at 12 months. CONCLUSION: ELCA is safe and effective for the treatment of in-stent restenosis. In the present sample, a slight increase in new restenotic lesions between 6 and 12 months was found.

Predictors of acute and long-term outcome with transluminal extraction atherectomy: the New Approaches to Coronary Intervention (NACI) registry.

The New Approaches to Coronary Intervention (NACI) registry was established to define the role of new coronary devices in overcoming the limitations of balloon angioplasty. The purpose of the present study was to evaluate the acute and long-term efficacy of the transluminal extraction catheter (TEC) device utilizing data from the NACI registry and identify clinical and anatomic patient subsets who may benefit from this device. From 1990-1994, >4,300 patients from 39 clinical sites enrolled consecutive patients treated with one of the 7 new devices to the NACI registry. The study population consists of 331 patients (385 lesions) treated with planned TEC as the sole new device. Of these patients, 243 (292 lesions) were treated for saphenous vein graft (SVG) disease and 88 (93 lesions) for native disease. Patients undergoing SVG treatment were older and more likely to be male. They had lower ventricular function, more unstable angina, and a higher incidence of congestive heart failure. Multivessel disease was more prevalent in the SVG cohort, as was evidence of thrombus before treatment. Although device success was achieved in 50% of SVG lesions and 41% of native lesions, lesion success was achieved in 90% and 78%, respectively, after adjunctive balloon angioplasty, and procedure success rates were 86% and 79%, respectively. The in-hospital major complication (death/Q-wave myocardial infarction/emergency coronary artery bypass graft [CABG] surgery) rate was higher in the SVG cohort (6.2% vs 2.3%), mainly due to higher mortality rate (5.3% vs 1.1%). Multivariate analysis showed that SVG was not an independent predictor for either an in-hospital major complication or clinical failure. The risk factors for major in-hospital complications were history of congestive heart failure (odds ratio = 3.17) and thrombus (odds ratio = 3.36). For clinical failure the risk factors were diabetes (odds ratio = 1.88), thrombus (odds ratio = 2.08), and calcium (odds ratio = 3.09). One-year rates of death, Q-wave myocardial infarction, or any repeat revascularization were 51% in the SVG cohort and 41% in the native cohort. Following adjustment, patients treated for SVG disease did not have a higher risk when compared with those treated for native disease. The factors significantly associated with this composite event at 1 year are male (relative risk = 1.41), patients with history of congestive heart failure (relative risk = 1.56), and total occlusions (relative risk = 1.52). This study shows that for both SVG and native cohorts, device success rates were low with TEC alone, but acceptable lesion success rates were achieved when adjunctive PTCA was used. In-hospital as well as 1-year major complications were higher in the SVG cohort. However, after adjusting for other risk factors, SVG attempt was not significantly associated with either in-hospital or 1-year events.

Excimer laser coronary angioplasty: the New Approaches to Coronary Intervention (NACI) experience.

In the New Approaches to Coronary Intervention (NACI) registry, 887 patients were electively treated with excimer laser coronary angioplasty (ELCA) for coronary artery disease. The Advanced Interventional System (AIS) system was used in 487 cases; the Spectranetics system, in 400. The mean age was 63.4 years. Most patients had unstable angina (60.3%); 43.7% had a prior myocardial infarction; and 18.6% were high risk or inoperable patients. Mean ejection fraction was 55.4%. A total of 1,000 lesions were treated in the 887 patients. Of the 1,000 lesions treated with ELCA in the 887 patients, 36% were in the right coronary artery; 33%, left anterior descending; 13%, circumflex; 3%, left main; and 16.6%, vein graft. By angiographic core laboratory analysis available for 752 (85%) patients with 839 lesions, lesions were 12.76 mm long. The minimum lumen diameter increased to 1.29 mm after the laser and finally to 1.95 mm after adjunctive percutaneous transluminal coronary angioplasty (PTCA) (which was performed in 93% of all lesions), with a final residual stenosis of 32.1% and Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow in 95%. Dissections of grades B, C, or D were seen after 22.0% of initial laser attempts, and postlaser perforations were noted in 2.6%. Additional such dissections accumulated after adjunctive PTCA but the perforation rate remained low. Procedural success was achieved in 84% of patients, but 1.2% died, 0.7% experienced Q-wave myocardial infarction (MI), and 2.7% required emergency bypass surgery. Multiple logistic regression analysis could not identify any independent predictors of these in-hospital complications. One-year mortality was 5.7% and the cumulative incidence of Q-wave MI was 1.5%. Coronary artery bypass graft (CABG) surgery was performed in 15.0% of patients whereas 25.5% required repeat percutaneous intervention with a target lesion revascularization rate of 31%. Independent predictors of death, Q-wave MI, or target lesion revascularization (which, combined, occurred in 35.6% of patients) were the absence of prior MI, ELCA in the circumflex, perforation after the procedure, and small (<2 mm) final minimal lumen diameter. Considering the large number of patients with high-risk lesions, laser angioplasty was performed with excellent procedural success rates and a reasonable incidence of major complications.

Bailout and corrective use of Gianturco-Roubin flex stents after percutaneous transluminal coronary angioplasty: operator reports and angiographic core laboratory verification from the National Heart, Lung, and Blood Institute/New Approaches to Coronary Intervention Registry.

OBJECTIVES: We sought to determine the in-hospital clinical outcome and angiographic results of patients prospectively entered into the National Heart, Lung, and Blood Institute/New Approaches to Coronary Intervention (NHLBI/NACI) Registry who received Gianturco-Roubin stents as an unplanned new device. BACKGROUND: Between August 1990 and March 1994, nine centers implanted Gianturco-Roubin flex stents as an unplanned new device in the initial treatment of 350 patients (389 lesions) who were prospectively enrolled in the NHLBI/NACI Registry. METHODS: Patients undergoing implantation of the Gianturco-Roubin flex stent were prospectively entered into the Gianturco-Roubin stent portion of the NHLBI/NACI Registry. Only subjects receiving the Gianturco-Roubin stent as a new device in an unplanned fashion are included. RESULTS: The mean age of the patient group was 61.8 years, and the majority of the patients were men. A history of percutaneous transluminal coronary angioplasty (PTCA) was present in 35.4% of the group, and 16.9% had previous coronary artery bypass graft surgery. Unstable angina was present in 67.7%. Double- or triple-vessel coronary artery disease was present in 55.4%, and the average ejection fraction was 58%. The presence of thrombus was noted in 7.3%, and 7.2% had moderate to severe tortuosity of the lesion. The angiographic success rate was 92%. Individual clinical sites reported that 66.3% of the stents were placed after suboptimal PTCA, 20.3% for abrupt closure and 13.4% for some other technical PTCA failure. Major in-hospital events occurred in 9.7% of patients, including death in 1.7%, Q wave myocardial infarction in 3.1% and emergency bypass surgery in 6%. Abrupt closure of a stented segment occurred in 3.1% of patients at a mean of 3.9 days. Cerebrovascular accident occurred in 0.3%, and transfusion was required in 10.6%. Vascular events with surgical repair occurred in 8.6% of patients. CONCLUSIONS: Despite these complications, the use of this device for the treatment of a failed or suboptimal PTCA result remains promising given the adverse outcome of abrupt closure with conventional (nonstent) treatment.

Quality control in the United States.

On a per capita basis, PTCA is more than three times more prevalent in the United States than in any other country. The US has nearly 1,000 institutions and 7,000 physicians doing angioplasty. Mortality and emergency bypass surgery rates are inversely proportional to angioplasty volume. Although PTCA is more prevalent in the United States, operators in other countries do more cases than do their US counterparts. Multiple forces control quality in the United States. Economic, political and legal forces are all important.

Randomised trial of excimer laser angioplasty versus balloon angioplasty for treatment of obstructive coronary artery disease.

BACKGROUND: Excimer laser coronary angioplasty is reported to give excellent procedural results for treatment of complex coronary lesions, but this method has not been compared with balloon angioplasty in a randomised trial. METHODS: Patients (n = 308) with stable angina and coronary lesions longer than 10 mm on visual assessment were included. 151 patients (158 lesions) were assigned randomly to laser angioplasty and 157 (167 lesions) to balloon angioplasty. The primary clinical endpoints were death, myocardial infarction, coronary bypass surgery, or repeat coronary angioplasty of the randomised segment during 6 months of follow-up. The primary angiographic endpoint was the minimal lumen diameter at follow-up in relation to the baseline value (net gain), as determined by quantitative coronary angiography. FINDINGS: Laser angioplasty was followed by balloon angioplasty in 98% of procedures. The angiographic success rate was 80% in patients treated with laser angioplasty compared with 79% in patients treated with balloon angioplasty. There were no deaths. Myocardial infarction, coronary bypass surgery, and repeat angioplasty occurred in 4.6%, 10.6%, and 21.2%, respectively, of the patients in the laser angioplasty group compared with 5.7%, 10.8%, and 18.5% of the balloon angioplasty group. Net mean (SD) gain in minimal lumen diameter was 0.40 (0.69) mm in patients treated with laser angioplasty and 0.48 (0.66) mm in those treated with balloon angioplasty (p = 0.34). The restenosis rate (> 50% diameter stenosis) was 51.6% in the laser angioplasty group versus 41.3% in the balloon angioplasty group (p = 0.13). INTERPRETATION: Excimer laser angioplasty followed by balloon angioplasty provides no benefit additional to balloon angioplasty alone with respect to the initial and long-term clinical and angiographic outcome in the treatment of obstructive coronary artery disease.

Effect of thromboxane A2 blockade on clinical outcome and restenosis after successful coronary angioplasty. Multi-Hospital Eastern Atlantic Restenosis Trial (M-HEART II)

BACKGROUND: Antithromboxane therapy with aspirin reduces acute procedural complications of coronary angioplasty (PTCA) but has not been shown to prevent restenosis. The effect of chronic aspirin therapy on long-term clinical events after PTCA is unknown, and the utility of more specific antithromboxane agents is uncertain. The goal of this study was to assess the effects of aspirin (a nonselective inhibitor of thromboxane A2 synthesis) and sulotroban (a selective blocker of the thromboxane A2 receptor) on late clinical events and restenosis after PTCA. METHODS AND RESULTS: Patients (n = 752) were randomly assigned to aspirin (325 mg daily), sulotroban (800 mg QID), or placebo, started within 6 hours before PTCA and continued for 6 months. The primary outcome was clinical failure at 6 months after successful PTCA, defined as (1) death, (2) myocardial infarction, or (3) restenosis associated with recurrent angina or need for repeat revascularization. Neither active treatment differed significantly from placebo in the rate of angiographic restenosis: 39% (73 of 188) in the aspirin-assigned group, 53% (100 of 189) in the sulotroban group, and 43% (85 of 196) in the placebo group. In contrast, aspirin therapy significantly improved clinical outcome in comparison to placebo (P = .046) and sulotroban (P = .006). Clinical failure occurred in 30% (49 of 162) of the aspirin group, 44% (73 of 166) of the sulotroban group, and 41% (71 of 175) of the placebo group. Myocardial infarction was significantly reduced by antithromboxane therapy: 1.2% in the aspirin group, 1.8% in the sulotroban group, and 5.7% in the placebo group (P = .030). CONCLUSIONS: Thromboxane A2 blockade protects against late ischemic events after angioplasty even though angiographic restenosis is not significantly reduced. While both aspirin and sulotroban prevent the occurrence of myocardial infarction, overall clinical outcome appears superior for aspirin compared with sulotroban. Therefore, aspirin should be continued for at least 6 months after coronary angioplasty.

PTCA, thrombolysis or atherectomy: rational treatment of recently occluded saphenous vein grafts.

Recently occluded saphenous vein grafts (SVG) contain abundant thrombus. Distal embolization and myocardial infarction often occur when recanalization of such SVG is attempted. In 80 patients with occluded SVG, we employed transcatheter devices to lyse, compress or extract thrombus. Primary treatment for these SVG was performed in the following manner; PTCA 29, intragraft urokinase 12, TEC atherectomy 39. Following urokinase or atherectomy, adjunctive PTCA was performed to diminish the residual stenosis. All patients had class III or IV angina. Clinically, SVG occlusions were 3 days to 3 months old. TIMI flow was grade 0, and occlusion length was greater than 6 cm for all SVG. Each strategy resulted in a similar procedure success rate. However, when used as a primary treatment, TEC may be associated with lower rates of distal embolization and myocardial infarction.

Transluminal extraction catheter for the treatment of diseased saphenous vein grafts: a multicenter experience.

To evaluate the efficacy, safety, and long-term results of atherectomy using the Transluminal Extraction catheter (TEC), patients with diseased saphenous vein grafts were enrolled in a prospective nonrandomized trial. Patients were followed to hospital discharge for acute complications and underwent routine 6-mo reevaluation with repeat cardiac catheterization to assess restenosis. Atherectomy was performed on 650 graft lesions in 538 consecutive patients (male 81%; mean age 66 yr; range 37-81). Mean graft age was 8.3 yr; (range 0.3-20) with 85% of grafts > 3 yr of age. Complex lesion morphology included thrombus (28%), ulceration (13%), and eccentricity (50%). Lesion success was achieved in 606 lesions (93%) with clinical success in 479 patients (89%). Lesion success was achieved in 90% of thrombus containing lesions, 97% of ulcerated lesions, and 97% of grafts > 3 yr. Complications included nonfatal myocardial infarction in 4 (0.7%) of patients, emergency bypass surgery in 2 (0.41%), and in-hospital death in 17 patients (3.2%). Angiographic follow-up at 6 mo was obtained from 268 lesions in 227 patients. The overall lesion angiographic restenosis rate was 60%. TEC atherectomy can be performed in patients with diseased saphenous vein grafts with high primary success and low complication rates. It is suitable for use in aged grafts, particularly in the presence of thrombus and ulcerations, and may be superior to balloon angioplasty alone in this group of patients.

Voda guiding catheter is superior to amplatz guiding catheter for performing left circumflex PTCA.

Amplatz guiding catheters have traditionally been recommended for performing Left Circumflex PTCA because of their enhanced support. The Voda (Scimed Inc.) design guiding catheter may provide similar support for the left coronary artery, particularly the left circumflex, with less catheter manipulation. We prospectively randomized 40 patients to either Amplatz or Voda guiding catheters to compare ease of use and observed that a Voda design guiding catheter has more favorable characteristics for use without sacrificing support.

A randomized comparison of the effects of gradual prolonged versus standard primary balloon inflation on early and late outcome. Results of a multicenter clinical trial. Perfusion Balloon Catheter Study Group.

BACKGROUND: Observational studies have suggested that prolonged balloon inflation during coronary angioplasty is associated with a high clinical success rate. This randomized clinical trial sought to evaluate the impact of primary gradual and prolonged inflations versus standard short dilatations in patients undergoing elective angioplasty. METHODS AND RESULTS: In phase 1 of the study, patients were randomized to receive two to four standard (1 minute) dilatations or one or two prolonged (15 minutes) dilatations after a perfusion balloon had been placed across a single target lesion. Patients with unsuccessful angiographic appearance after phase 1 dilatations had further dilatations in phase 2. Patients were followed for 6 to 12 months after the procedure. Of 478 patients, 242 received a median of one prolonged dilatation of 15 minutes' duration, and 236 received three dilatations for a median of 1 minute. Patients assigned to prolonged dilatations had a higher success rate (< or = 50% residual visual stenosis) (95% versus 89%; P = .016), less severe residual stenosis by quantitative angiography (median [25th and 75th percentiles], 35% [26%, 42%] versus 38% [30%, 46%]; P = .001), and a lower rate of major dissections (3% versus 9%; P = .003) at the end of phase 1. A total of 114 patients had further dilatations in phase 2-43 in the prolonged arm and 71 in the standard arm. The final procedural success rate was 98% with both primary dilatation strategies, which included additional maneuvers such as prolonged dilatations in the patients randomized to the primary standard dilatation. Overall, 320 of 416 patients (77%) who were discharged after a successful procedure without any in-hospital event (death, myocardial infarction, coronary artery bypass graft surgery, abrupt closure, or repeat angioplasty in target vessel) returned for follow-up angiography. The restenosis rate (> 50% residual visual stenosis) was 44% (95% confidence interval, 37% to 52%) in the prolonged dilatation group and 44% (36% to 52%) in the standard dilatation group. The primary angiographic end point of failure at the end of phase 1, abrupt closure, or restenosis throughout the study period was similar in both groups (prolonged, 51%; standard, 49%; P = .62). The secondary end point of absence of clinical events (death, nonfatal myocardial infarction, coronary artery bypass graft surgery, or repeat angioplasty in target vessel) also was similar (prolonged, 66%; standard, 74%; P = .15). CONCLUSIONS: Primary gradual and prolonged dilatations caused less arterial trauma with a modestly larger arterial lumen compared with standard dilatations. This initial improvement in angiographic appearance did not lead to a significant reduction in restenosis or clinical adverse events during follow-up.

Hockey stick guiding catheter.

Guiding catheter strategies form an important component of successful PTCA. Selection of appropriate guiding catheters is essential for providing adequate back-up support and visualization. Hockey stick guiding catheters are an excellent choice for performing PTCA of the right coronary artery and for saphenous vein grafts.

Excimer laser coronary angioplasty.

Recent experience with excimer laser coronary angioplasty (ELCA) has shown the safety and efficacy of the technique in the treatment of coronary stenosis, with results similar to percutaneous transluminal coronary angioplasty (PTCA). Several advantages of the excimer laser for intravascular use have been identified by the ELCA Registry, a group of 15 institutions nationally that have pooled data on their cooperative experience with ELCA. Advantages include the ability of the laser to ablate atheroma with microscopic precision without thermal injury and the ability of vessel surfaces to heal without scarring. The initial results of the multicenter investigation of ELCA in 958 patients indicate that ELCA may be indicated particularly for long, diffuse lesions. With the advent of larger diameter catheters, ELCA is a viable alternative to PTCA. Restenosis was seen as a significant problem, and it remained problematic at 6-month follow-up. In comparison with conventional balloon angioplasty, ELCA may eliminate that component of restenosis due to inadequate dilation or elastic recoil, but it does not appear to affect restenosis caused by smooth muscle proliferation. Catheter design and energy delivery continue to evolve and may affect future results of laser coronary angioplasty.

Multi-Hospital Eastern Atlantic Restenosis Trial. II: A placebo-controlled trial of thromboxane blockade in the prevention of restenosis following coronary angioplasty.

Since platelet interactions appear to play an important role in the development of restenosis, attenuation of thromboxane-mediated reactions may improve the long-term outcome following coronary angioplasty. Phase II of the Multi-Hospital Eastern Atlantic Restenosis Trial (M-HEART) is a prospective, randomized, placebo-controlled study of thromboxane blockade in the prevention of restenosis following successful coronary angioplasty. Two forms of thromboxane blockade are evaluated: aspirin (a nonspecific inhibitor of thromboxane synthesis) and sulotroban (a specific thromboxane receptor antagonist). The design of this multicenter trial and the rationale for use of sulotroban in the prevention of restenosis are reviewed in this report.

Diffuse embolization following percutaneous transluminal coronary angioplasty of occluded vein grafts: the blush phenomenon.

Percutaneous transluminal coronary angioplasty (PTCA) was performed on 146 saphenous vein grafts in 116 patients. In 29 patients, 31 grafts were totally occluded. Myocardial staining lasting over 5 minutes--"the blush phenomenon"--followed the opening of the occluded grafts in 9 of these patients. In 5 of these 9, enzyme release suggested infarction. A sixth patient died within a few hours of PTCA, with suspected infarction. Autopsy demonstrated diffuse and extensive distal coronary arterial embolization of grumous material, including cholesterol crystals, platelets, and fibrin. The blush phenomenon was not seen following PTCA in the remaining 20 patients with total occlusions, nor in any of the 87 patients with stenosed grafts. We have not observed the blush phenomenon following PTCA of more than 3300 coronary arteries. Of the 9 patients demonstrating the blush phenomenon, 6 had a recent history of myocardial infarction or unstable angina pectoris, compared with 4 of the remaining 20 patients with occluded grafts. We now approach occluded grafts with injection of intragraft thrombolytic agents or with atherectomy prior to PTCA. Future approaches may include atherectomy or laser angioplasty.

Clinical and angiographic determinants of primary coronary angioplasty success. M-HEART Investigators.

Clinical and anatomic determinants of the initial success of percutaneous transluminal coronary angioplasty were prospectively evaluated in 826 patients enrolled in the Multi-Hospital Eastern Atlantic Restenosis Trial (M-HEART). The 639 men and 187 women ranged in age from 31 to 85 years. Successful angioplasty (residual stenosis less than 50% and no major complications) was achieved in 886 (88.6%) of 1,000 lesions. Success rates were uniform among the eight individual centers. Outcome was not influenced by gender, age or other clinical features, including severity and duration of angina, prior myocardial infarction, rest pain, transient ST segment elevation, history of smoking or diabetes. In contrast, procedural outcome was significantly associated with lesion-specific angiographic factors. Stenoses 60% to 74%, 75% to 89%, 90% to 99% and 100% were associated with success rates of 96%, 90%, 84% and 69%, respectively (p less than 0.001). Angioplasty was less successful in calcified than in noncalcified lesions (82% versus 90%, p less than 0.01), in thrombotic than in nonthrombotic lesions (82% versus 90%, p less than 0.05) and in lesions in the right coronary artery than in other vessels (84% versus 90%, p less than 0.01). Outcome was not related to other anatomic variables, including lesion location (proximal versus distal), vessel size, eccentricity, stenosis length or translesional gradient. By multivariate logistic regression, preangioplasty percent stenosis, right coronary artery location and lesion calcification were demonstrated to be significant independent predictors of angioplasty success. Alternative clinical and angiographic variables did not contribute to this regression model.(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous excimer laser coronary angioplasty.

To determine the efficacy of percutaneous excimer laser coronary angioplasty as an adjunct or alternative to conventional balloon angioplasty, 55 patients were studied in a multicenter trial. These patients underwent the procedure using a modification of conventional balloon angioplasty technique. A first-generation, 1.6-mm diameter catheter constructed of 12 individual silica fibers concentrically arranged around a guidewire lumen was used. Catheter tip energy density varied from 35 to 50 mJ/mm2. The mean number of pulses delivered at 20 Hz was 1,272 +/- 1,345. Acute success was defined as a greater than or equal to 20% increase in stenotic diameter and a lumen of greater than or equal to 1 mm in diameter after laser treatment. Acute success was achieved in 46 of 55 (84%) patients. Adjunctive balloon angioplasty was performed on 41 patients (75%). The percent diameter stenosis as determined by quantitative angiography decreased from a baseline of 83 +/- 14 to 49 +/- 11% after laser treatment and to 38 +/- 12% in patients undergoing adjunctive balloon angioplasty. The mean minimal stenotic diameter increased from a baseline of 0.5 +/- 0.4 to 1.6 +/- 0.5 mm after laser treatment and to 2.1 +/- 0.5 mm after balloon angioplasty. There were no deaths and no vascular perforations. One patient (1.8%) required emergency coronary bypass surgery. These data suggest that excimer laser energy delivered percutaneously by specially constructed catheters can safely ablate atheroma and reduce coronary stenoses.